Mo. Rev. Stat. § 84.330: Police force members are officers of state.

The members of the police force of the cities covered by sections 84.010 to 84.340, organized and appointed by the police commissioners of said cities, are hereby declared to be officers of the said cities, under the charter and ordinances thereof, and also to be officers of the state of Missouri, and shall be so deemed and taken in all courts having jurisdiction of offenses against the laws of this state or the ordinances of said cities.